Thermal Comfort in the Passenger Compartment Using a 3-D Numerical Analysis and Comparison with Fanger’s Comfort Models

Abstract

The paper presents the human thermal comfort inside a car cabin using three-dimensional numerical analysis and state of the art comfort models. Vehicular thermal comfort is a must concern factor in modern car manufacturing industries. Numerical simulations have been performed to accurately predict the temperature inside the car cabin and velocity of airflow. The numerical results are then compared using Fanger’s model, the equivalent temperature model and the modified Fanger’s model. A link has been developed using a general thermal comfort index for the considered human thermal comfort models. The general thermal comfort index takes into consideration all the investigated parameters that affect the vehicular thermal comfort thereby evaluating the whole car environment. The thermally comfortable conditions for the driver and passengers in a vehicular cabin are also addressed based on some of the thermal comfort indexes available in literature. In addition, the solar load has also been added using a surface radiation model to consider the environmental heat load effect on cabin thermal comfort.

Theoretical studies of the heating system in the vehicle compartment during passenger transportation taking into account breathing under conditions of low temperatures

“…Тk was assumed to be equal to 328 K, according to investigation [48]. Characteristics of materials used in the simulation are presented in Table 1 which was compiled based on data of papers [31,45,48]. The calculation of microclimate parameters in the considered cross-section of the vehicle compartment was performed in ANSYS Fluent software suit.…”

“…The paper [26] describes the most currently known methods of thermal comfort assessment. The development of microclimate regulation systems is presented in papers [8,21,27,28], and the assessment of their performance by such indicators as energy consumption, thermal comfort and air quality is presented in papers [6,12,13,29,30,31,32,33]. Theoretical studies of microclimate regulation systems and microclimate effect on humans are based on computer models described in papers [3,5,7,9,10,25,27,28,29,33].…”

“…The increase in accuracy of the thermodynamic model implementations on the computer is provided due to the congruence of 3D models, the use of advanced computational algorithms and taking into account all participants in the heat balance creation, according to papers [31,33,38]. Thus, accounting for friction and aerodynamic forces in providing thermal comfort is discussed in paper [32], and the role of solar radiation and radiation of the interior panels is discussed in papers [11,27,31]. In paper [39] a description of the main parameters of the microclimate in the car compartment and the factors inherent to passengers are presented.…”

“…The research trend of human external respiration is developed from the point of view of chemical compounds distribution in the human breathing zone and penetration of the substances into his body, or from the point of view of a human being as a source of external environment pollution, according to papers [43,44,45]. Thus, for the moment researches of the effect of practically all elements of the wheeled vehicle technical system on the achievement of thermal comfort in the compartment have been conducted, as can be seen from papers [31,32,46]. The assessment of arising subjective sensations of passengers under certain microclimatic conditions is presented in papers [7,17,26].…”

“…It has been established that the parameters of microclimate in the compartment during movement are not constant, as well as subjective sensations of thermal comfort are different when the vehicle is moving and when it is motionless, as demonstrated in papers [11,16,17]. However, almost all papers consider the thermal comfort provision in conditions of heating microclimate which can be found in papers [9,10,12,15,17,18,19,25,27,29,31,33]; at the same time passengers represent passive receptors in the context of the environment, as is proven in paper [43]. Therefore, assessment of heating system effi ciency under conditions of cooling microclimate in the cold period of the year and determination of actual values of microclimate parameters in the compartment for wheeled vehicles of M3 category with the seating capacity not exceeding 22 passengers, taking into account the external respiration of a person as a constituent element in providing thermal comfort, is one of the further research trends in regulation of microclimate of the passenger compartment of the wheeled vehicle.…”